Imaging apparatus

• US 20030151673A1
• Filed: 03/14/2002
• Published: 08/14/2003
• Est. Priority Date: 03/16/2001
• Status: Active Grant

• Current Assignee: Olympus Corporation
• Original Assignee: Olympus Optical Company Ltd. (Olympus Corporation)
• Inventors: Kijima, Takayuki, Mori, Keiichi, Yoshida, Hideaki, Hashimoto, Hitoshi
• Granted Patent: US 7,365,783 B2
• Time in Patent Office: Days
• US Class Current: 348/220.1
• CPC Class Codes: H04N 25/683 by defect estimation performed on the scene signal, e.g. real time or on the fly detection

Abstract

An imaging apparatus comprises an imaging element, an imaging optical system configured to input an image of an object to the imaging element, a non-volatile memory part for storing defect data concerning the imaging element, and includes a first memory area storing initial defect data concerning the imaging element, and a second memory area different from the first memory area, a defect detection part for detecting defect data concerning the imaging element, and a control part for controlling reading and writing of the defect data on the imaging element from and to the non-volatile memory part, the control part writing, to the second memory area, defect data detected by the defect detection part.

Claims

1. An imaging apparatus comprising:

an imaging element;

an imaging optical system configured to input an image of an object to the imaging element;

non-volatile memory means for storing defect data concerning the imaging element, the non-volatile memory means including a first memory area which stores initial defect data concerning the imaging element, and a second memory area different from the first memory area;

defect detection means for detecting defect data concerning the imaging element; and

control means for controlling reading and writing of the defect data on the imaging element from and to the non-volatile memory means, the control means writing, to the second memory area, defect data detected by the defect detection means.

2. An imaging apparatus according to claim 1, wherein defect data to be written by the control means to the second memory area is post defect data included in the defect data detected by the defect detection. means, the post defect data not overlapping the initial defect data stored in the first memory area.

3. An imaging apparatus according to claim 1, further comprising defect compensation means for executing, on an output from the imaging element, a compensation process using adjacent pixel data, on the basis of the defect data concerning the imaging element.

4. An imaging apparatus according to claim 3, wherein the defect data used by the compensation means in the compensation process is obtained by adding the initial defect data read from the first memory area, to the post defect data read from the second memory area.

5. An imaging apparatus according to claim 1, wherein the defect data is address data on a defective pixel.

6. An imaging apparatus comprising:

an imaging element;

an imaging optical system configured to input an image of an object to the imaging element;

defect data detection means for detecting pixel defect data concerning the imaging element on the basis of an output from the imaging element;

reliability determination means for determining reliability of the defect data detected by the defect data detection means on the basis of the output from the imaging element; and

control means for stopping detection of defect data by the defect data detection means if the reliability determination means determines that the reliability of the detected defect data is insufficient.

7. An imaging apparatus according to claim 6, wherein

the defect data detection means detects, as the pixel defect data, a defect address as an address corresponding to a pixel whose output is to be invalidated, and

the defect correction means executes, on a pixel whose address is registered as a defect address, a compensation process using an output from a pixel adjacent to the first-mentioned pixel.

8. An imaging apparatus according to claim 6, further comprising imaging light-shielding means for shielding the imaging element from light emitted from the imaging optical system, wherein

the defect data detection means detects the pixel defect data on the basis of a dark output obtained when the imaging light-shielding means shields the imaging element from the light emitted from the imaging optical system.

9. An imaging apparatus according to claim 8, wherein the reliability determination means determines the reliability of the detection on the basis of a comparison result between a mean level of dark outputs of pixels located in a predetermined area of the imaging element, and a predetermined determination criterion level.

10. An imaging apparatus comprising:

an imaging element;

an imaging optical system configured to input an image of an object to the imaging element;

defect data detection means for detecting pixel defect data concerning the imaging element on the basis of an output from the imaging element;

defect correction means for executing a defect correction process on the output from the imaging element, on the basis of defect data detected by the defect data detection means;

reliability determination means for determining reliability of the defect data detected by the defect data detection means on the basis of the output from the imaging element; and

control means for inhibiting execution of the defect correction process on the defect data detected by the defect data detection means, if the reliability determination means determines that the reliability of the detected defect data is insufficient.

11. An imaging apparatus according to claim 10, wherein

the defect data detection means detects, as the pixel defect data, a defect address as an address corresponding to a pixel whose output is to be invalidated, and

the defect correction means executes, on a pixel whose address is registered as a defect address, a compensation process using an output from a pixel adjacent to the first-mentioned pixel.

12. An imaging apparatus according to claim 10, further comprising imaging light-shielding means for shielding the imaging element from light emitted from the imaging optical system, wherein

the defect data detection means detects the pixel defect data on the basis of a dark output obtained when the imaging light-shielding means shields the imaging element from the light emitted from the imaging optical system.

13. An imaging apparatus according to claim 12, wherein the reliability determination means determines the reliability of the detection on the basis of a comparison result between a mean level of dark outputs of pixels located in a predetermined area of the imaging element, and a predetermined determination criterion level.

14. An imaging apparatus comprising:

an imaging element;

an imaging optical system configured to input an image of an object to the imaging element;

memory means which registers, as defect data, an address corresponding to a defective pixel in the imaging element;

defect compensation means for executing a compensation process on an output from the defective pixel, using an output from a pixel located adjacent to the defective pixel, on the basis of the defect data registered in the memory means;

defect data detection means for detecting a pixel defect address related to the imaging element on the basis of an output from the imaging element;

defect data additional registration means for additionally registering, as to-be-additionally-registered defect data in the memory means, at least part of pixel defect addresses corresponding to defect data newly detected by the defect data detection means;

reliability determination means for determining reliability of the to-be-additionally-registered defect data; and

additional registration control means for stopping additional registration of defect data by the defect data additional registration means, if the reliability determination means determines that the reliability of the to-be-additionally-registered defect data is insufficient.

15. An imaging apparatus according to claim 14, wherein the to-be-additionally-registered defect data is a pixel address included in the defect data newly detected by the defect data detection means, the pixel address not overlapping pixel defect addresses corresponding to the defect data registered in the memory means.

16. An imaging apparatus according to claim 14, wherein the defect compensation means executes the compensation process on the basis of both the registered defect data and detect data newly detected at a present stage by the defect data detection means.

17. An imaging apparatus according to claim 16, wherein the defect compensation means executes the compensation process on the basis of the registered defect data alone, if the reliability determination means determines that the reliability of the to-be-additionally-registered defect data is insufficient.

18. An imaging apparatus according to claim 14, further comprising imaging light-shielding means for shielding the imaging element from light emitted from the imaging optical system, wherein

the defect data detection means detects the pixel defect data on the basis of a dark output obtained when the imaging light-shielding means shields the imaging element from the light emitted from the imaging optical system.

19. An imaging apparatus according to claim 18, wherein the reliability determination means determines that the reliability of defective-pixel detection is insufficient if to-be-additionally-registered defective pixels all have a dark output level equal to a predetermined saturation level.

20. An imaging apparatus according to claim 14, wherein the reliability determination means determines reliability of the to-be-additionally-registered defect data on the basis of an output from the imaging element.

21. An imaging apparatus comprising:

defective-pixel detection means for detecting defective pixels in an imaging element on the basis of a dark output from the imaging element obtained after exposure is executed for a predetermined period of time in a light shielded state;

reliability determination means for determining reliability of defective-pixel detection in accordance with the dark output in a predetermined portion of an imaging area of the imaging element; and

non-volatile memory means for storing pixel address data concerning that one of the detected defective pixels, whose detection reliability is determined to be high.

22. An imaging apparatus according to claim 21, wherein the non-volatile memory means has a first area to which writing is executed in a manufacturing process, and a second area to which writing is executed at any arbitrarily-selected point in time, defective-pixel data stored in the second area not including data registered in the first area.